The present invention relates to a process for the in-situ production of a sorbent-oxide aerosol with promoter used for removing effluents from a gaseous combustion stream and, more particularly, a process for the production of a metal oxide sorbent with promoter which absorbs sulfur and other effluents from a hydrocarbon fuel combustion stream.
Gaseous combustion streams are the source of many undesirable effluents discharged into the environment which result in atmospheric pollution. The undesirable effluents include, for example, sulfur, nitrogen, chlorium flourine and a host of other undesirable effluents. Particularly harmful to the environment are the undesirable effluents which result from the combustion of hydrocarbon containing fossil fuels.
Heretofore, many processes have been proposed for removing effluents from combustion streams. In the case of sulfur, nitrogen and other like effluents it is common practice to scrub the gaseous streams. In addition, in-furnace dry sorbent injection has been commonly employed. Neither of these processes tend to be cost effective on a commercial level.
Naturally, it would be highly desirable to improve the process for removing effluents from industrial combustion streams as disclosed in co-pending U.S. patent application Ser. No. 498,952 pending. Co-pending U.S. patent application Ser. No. 498,952 pending discloses an improved process for removing effluents from a hydrocarbon fuel combustion stream wherein a sorbent-oxide aerosol is produced in-situ during combustion of the hydrocarbon fuel. The process is a great improvement over previously known processes.
Co-pending U.S. patent application Ser. No. 498,952 pending discloses that the generation of the sorbent oxide aerosol is achieved, in part, by dissolving an effluent sorbent compound in water, and mixing this aqueous solution with the fuel either prior or at the time of combustion. Co-pending U.S. patent application Ser. No. 498,952 pending also discloses that by optimizing parameters associated with the atomization and/or combustion of the fuel/sorbent mixture, the generation of the sorbent-oxide aerosol, and therefore the effluent absorption can be greatly enhanced.
Japanese Patents 75-26,766(1975) and 75-46,562(1975) disclose that by mixing the fuel and an aqueous solution of the effluent sorbent, higher levels of SO.sub.2 removal can be achieved compared to the Dry Sorbent Injection technology. They fail to recognize, however, that by optimizing the combustion conditions the performance can be improved.
The process of the present invention represents an improvement over those previously described, since by adding small amounts of a sulfation promoter to the aqueous solution containing the sorbent compound the removal of the effluent is greatly enhanced, upon generation of the sorbent oxide aerosol.
Japanese Patent 78-39,965(1978), Japanese Patent 84-90,619 (1984), and U.S. Pat. No. 4,191,115 (1980), have disclosed that by mixing a sulfation promoter with CaCO.sub.3 or CaO an enhancement in the absorption of SO.sub.2 from a gas stream can be achieved. The process of the present invention represents an improvement over these processes because the sorbent-oxide aerosol with promoter is more reactive toward SO.sub.2 and therfore a much higher level of SO.sub.2 removal can be achieved.
Accordingly, it is a principal object of the present invention to provide a process for removing environmental harmful effluents from a gaseous stream.
It is a particular object of the present invention to provide a process for the in-situ production of a sorbent-oxide aerosol with promoter for removing effluents from a gaseous combustion stream which is effective and economical.
It is a still further object of the present invention to provide a process for the production of a sorbent-oxide stream with promoter which is useful for removing sulfur and other effluents from a gaseous hydrocarbon fuel combustion stream.
Further objects and advantages of the present invention will appear herein below.